U.S. patent application number 11/323487 was filed with the patent office on 2008-01-24 for high power light-emitting diode package comprising substrate having beacon.
This patent application is currently assigned to KOREA PHOTONICS TECHNOLOGY INSTITUTE. Invention is credited to Tae-Hoon Kim, Young-Woo Kim, Young-Moon Yu.
Application Number | 20080019133 11/323487 |
Document ID | / |
Family ID | 37183112 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080019133 |
Kind Code |
A1 |
Kim; Young-Woo ; et
al. |
January 24, 2008 |
High power light-emitting diode package comprising substrate having
beacon
Abstract
Disclosed herein is a package structure including at least one
high power light-emitting diode to exhibit excellent heat release
properties. In the package structure, a light-emitting diode chip
which generates heat is directly attached to a beacon processed to
protrude from part of a heat spreader having high heat
conductivity, whereby an electrical wiring portion is separated
from a heat release portion, thus maximizing heat release
properties and realizing high luminance and reliability. The
package structure is composed of a beacon formed on a metal or
non-metal substrate having high heat conductivity to mount a high
power light-emitting diode chip, to increase heat release
properties; a wiring portion provided on the same line as the diode
to input and output power and signals; and a reflection cup having
a cavity, which may be inserted into or attached to the heat
spreader or the wiring substrate, including a low temperature
co-fired ceramic substrate, a high temperature co-fired ceramic
substrate, or a printed circuit board.
Inventors: |
Kim; Young-Woo;
(Gwangsan-gu, KR) ; Kim; Tae-Hoon; (Buk-gu,
KR) ; Yu; Young-Moon; (Yuseong-gu, KR) |
Correspondence
Address: |
BAKER & HOSTETLER LLP
WASHINGTON SQUARE, SUITE 1100
1050 CONNECTICUT AVE. N.W.
WASHINGTON
DC
20036-5304
US
|
Assignee: |
KOREA PHOTONICS TECHNOLOGY
INSTITUTE
|
Family ID: |
37183112 |
Appl. No.: |
11/323487 |
Filed: |
December 30, 2005 |
Current U.S.
Class: |
362/294 |
Current CPC
Class: |
H01L 2924/00014
20130101; H01L 25/0753 20130101; H01L 2924/00012 20130101; H01L
2224/48091 20130101; H01L 2224/48091 20130101; H01L 33/60 20130101;
H01L 33/62 20130101; H01L 2224/48091 20130101; H01L 33/642
20130101 |
Class at
Publication: |
362/294 |
International
Class: |
F21V 29/00 20060101
F21V029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2005 |
KR |
10-2005-0064512 |
Claims
1. A high power light-emitting diode package comprising a substrate
having a beacon, comprising: a high power light-emitting diode to
emit light; a heat spreader to release heat generated from the high
power light-emitting diode and including a beacon formed thereon
for mounting of the high power light-emitting diode; a wiring
substrate to supply external electric power to the high power
light-emitting diode; and a reflection cup to increase emission
efficiency of light emitted from the high power light-emitting
diode.
2. The package as set forth in claim 1, further comprising a
phosphor formed on the high power light-emitting diode to determine
color of light emitted from the high power light-emitting
diode.
3. The package as set forth in claim 2, further comprising an
encapsulant provided on the phosphor.
4. The package as set forth in claim 1, wherein the high power
light-emitting diode is attached to the beacon of the heat spreader
using an adhesive.
5. The package as set forth in claim 1, further comprising a
conduction preventing layer formed between the wiring substrate and
the reflection cup to prevent electrical conduction
therebetween.
6. The package as set forth in claim 1, further comprising an
insulating layer formed between the wiring substrate and the heat
spreader to prevent short-circuit therebetween.
7. The package as set forth in claim 1, wherein a vertical section
of the beacon comprises a planar shape.
8. The package as set forth in claim 1, wherein a vertical section
of the beacon comprises a groove shape.
9. The package as set forth in claim 1, wherein a vertical section
of the beacon comprises a stepped shape.
10. The package as set forth in claim 1, wherein the heat spreader
is formed using at least one process selected from among an
extruding process, a molding process, and a plating process.
11. The package as set forth in claim 1, wherein the heat spreader
is plated with nickel to form a nickel plated layer, which is then
plated with silver or gold, upon bonding with the wiring
substrate.
12. The package as set forth in claim 1, wherein the reflection cup
is plated with silver to increase reflectance and luminance.
13. The package as set forth in claim 6, wherein the insulating
layer is formed of any one material selected from among low
temperature co-fired ceramic, high temperature co-fired ceramic,
ceramic, FR-4, epoxy, and mixtures thereof.
14. The package as set forth in claim 6, wherein the insulating
layer has a thickness of 50 .mu.m or more.
15. The package as set forth in claim 1, wherein a number of high
power light-emitting diodes mounted on a single beacon is one or
more.
16. The package as set forth in claim 15, further comprising a
connector to input external signals and electric power.
17. The package as set forth in claim 15, wherein a number of
beacons formed on a single heat spreader is one or more.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a high power light-emitting
diode (HP LED) package, which includes a predetermined substrate
having a protruding portion (hereinafter, referred to as a
`beacon`) to improve heat release performance and increase the
lifetime of the HP LED, by enabling direct mounting of the IHP LED,
which generates heat, on a metal or non-metal substrate having high
heat conductivity, and eliminating wiring, which functions to apply
signals and electric power, from a heat transfer path.
[0003] 2. Description of the Related Art
[0004] Generally, an LED, which is formed of a Group III-V or II-VI
compound semiconductor, including GaAs, AlGaAs, GaN, InGaN or
AlGaInP, is a diode-able to emit its excess energy in the form of a
photon upon coupling and recombination between electrons injected
into an N layer and holes of a P layer through application of
current. For example, there are a red LED using GaAsP, a green LED
using GaP, a blue LED using a double hetero structure of
InGaN/AlGaN, etc. Further, attempts to realize a white LED,
including appropriately. combining RGB (Red, Green, Blue) LEDs and
applying phosphor to the blue LED, have been made.
[0005] Although LEDs have been used as lamp type indicators to
date, their application to backlight units of flat panel displays,
general lighting fixtures, and automobiles, which can. be realized
by increasing the luminance and light emission thereof, is under
study.
[0006] Typically, an HP LED requires high luminance, a long
lifetime and superior reliability, and its performance and
properties are determined by color temperatures, luminance, and
luminance intensities. To increase luminous efficiency, methods of
increasing the degree of crystal growth of an active layer, an
electron-injecting (N) layer and a hole-injecting (P) layer of the
LED are first proposed. Additionally, the above performance of the
LED is determined by a structure that efficiently releases heat, a
controllable wiring structure, and a bonding process for connection
of the diode to the wiring substrate. In realizing high light
emission properties of the HP LED, the characteristics of the
compound semiconductor material greatly affect the HP LED, thus
various limitations are imposed on manufacturing such an LED.
Hence, research into LED package structures is actively being
carried out.
[0007] Moreover, the HP LED should have improved heat release
properties, in order to obtain a long lifetime and high
reliability. To this end, a surface mounted device (SMD) suitable
for increasing heat release properties has been developed as shown
in FIGS. 3, 4 and 5.
[0008] Referring to FIGS. 3, 4 and 5, a flip-chip bonding or
wire-bonding type HP LED 301a, 401a, 501a is attached to the upper
surface of a heat slug 301c, 401d, 501d using a solder or an
adhesive having improved heat conductivity 301b, 401b, 501b, after
which the heat slug is attached to the upper surface of a wiring
substrate using an adhesive having improved heat conductivity 301d,
401e, 501f. The wiring substrate includes a wiring layer 303, 402,
502 and an insulating layer 302, 403, 503 to electrically insulate
the wiring layer from a heat spreader 304, 404, 504 made of
aluminum (Al), copper (Cu), or ceramic (SiC, AlN or AlSiC) having
high heat conductivity, each of which is sequentially laminated on
the heat spreader. For bonding the wiring substrate with the heat
slug 301c, 401d, 501d, solder or adhesive having improved heat
conductivity 301d, 401e, 501f is used. In addition, a reflection
cup 401d is provided to improve the angle of light distribution
from the LED and the luminance of the LED. The heat generated from
the LED is simultaneously released through three pathways, that is,
conduction, convection and radiation. The heat is transferred
through the media connected to the LED, sequentially from the
medium having the highest heat conductivity to the medium having
the lowest heat conductivity. Therefore, heat is transferred
through conduction into the package, formed of a conductor and a
semiconductor having high heat conductivity, in an amount greater
than that transferred through convection and radiation out of the
package exposed to air having heat conductivity of 0.024 W/mK
(@.degree. C.). From this, it should be noted that heat is
preferably released from the package through conduction. With
respect to heat release, the principle of the conduction for
transferring heat to a predetermined region obeys a Fourier's law.
A heat transfer rate is represented by Equation 1 below: q = - k
.times. .times. A .function. ( d T d x ) Equation .times. .times. 1
##EQU1##
[0009] In Equation 1, q shows a heat transfer rate and is in
proportion to heat conductivity k of a medium to be conducted, an
area A thereof, and a change of temperature to distance dT/dx.
[0010] In the case where the HP LED coexists with a material having
low heat conductivity in a small space on a heat transfer-path, its
heat transfer rate is decreased. Further, thermal fatigue
accumulates in the HP LED. When electrons are injected into the N
layer of the HP LED, a scattering phenomenon occurs due to
collisions of lattice atoms of the semiconductor. The higher the
temperature, the more the lattice scattering. Thereby, electron
mobility and. forward voltage and current are decreased, and less
coupling and recombination with the holes result, thus the luminous
efficiency of the HP LED may be lowered and the HP LED may
malfunction. The individual structures shown in FIGS. 3, 4 and 5
include at least three barrier layers having low heat conductivity
upon transfer of heat from the HP LED to the heat spreader 304,
404, 504. As seen in FIGS. 3, 4 and 5, the first barrier layer is
the adhesive 301b, 401b, 501b having improved heat conductivity
used to attach. the HP LED 301a, 401a, 501a to the heat slug 301c,
401d, 501d, and has heat conductivity of 0.3.about.1 W/mK and a
thickness. of 50.about.150 .mu.m. The second barrier layer is the
solder or adhesive 301d, 40le, 501f used to attach the heat slug to
the wiring. layer 303, 402, 502 of the wiring substrate, and has
heat conductivity of 37.about.55 W/mK depending on the proportions
of tin (Sn) and lead (Pb) when using solder, and heat conductivity
of 0.3.about.1 W/mK when using adhesive having improved heat
conductivity, with a thickness of 50.about.100 .mu.m. The third
barrier layer is the insulating layer 302, 403, 503 of the wiring
substrate, and has heat conductivity of 0.35.about.23 W/mK and a
thickness of 50 .mu.m or more. Even if the types of HP LED mounted
in FIGS. 3, 4 and 5 are the same, the junction temperature of the
HP LED may be greatly increased by the kinds, thicknesses and
structures of heat transfer media. In particular, as the number of
junction layers having low heat conductivity is increased, these
layers function as heat barriers, thus increasing thermal fatigue.
Consequently, the HP LED becomes unreliable in view of long-term
operation and performance.
SUMMARY OF THE INVENTION
[0011] Accordingly, the present invention has been made keeping in
mind the above problems occurring in the related art, and an object
of the present invention is to provide an HP LED package, which is
advantageous because at least one LED is attached to the beacon of
a heat spreader formed of metal or non-metal having high heat
conductivity, and also. a wiring substrate is attached to the heat
spreader to separate a heat transfer path from an application
portion of electric power and signals, thus decreasing a junction
temperature and heat resistance of the HP LED, resulting in low
thermal fatigue, excellent heat release properties, and high
luminance.
[0012] In order to achieve the above object, the present invention
provides an HP LED comprising a substrate having a beacon,
comprising an HP LED to emit light; a heat spreader to release heat
generated from the HP LED and including a beacon formed thereon for
mounting of the HP LED; a wiring substrate to supply external
electric power to the HP LED; and a reflection cup to increase
luminous efficiency of the HP LED.
[0013] In the present invention, the HP LED preferably further
comprises phosphor formed on the HP LED to determine the color of
light emitted from the HP LED.
[0014] In the present invention, the HP LED preferably further
comprises an encapsulant provided on the phosphor.
[0015] In the present invention, the HP LED is preferably attached
to the beacon using an adhesive.
[0016] In the present invention, the HP LED preferably further
comprises a conduction preventing layer formed between the wiring
substrate and the reflection cup to prevent electrical conduction
therebetween.
[0017] In the present invention, the HP LED preferably further
comprises an insulating layer formed between the wiring substrate
and the heat spreader to prevent short-circuit therebetween.
[0018] In the present invention, a vertical section of the beacon
may be any one shape selected from among a planar shape, a groove
shape, and a stepped shape.
[0019] In the present invention, the heat spreader is preferably
formed using at least one process selected from among an extruding
process, a molding process, and a plating process.
[0020] In the present invention, the heat spreader is preferably
plated with nickel and then silver or gold upon bonding with the
wiring substrate.
[0021] In the present invention, the reflection cup is preferably
plated with silver to increase reflectance and luminance.
[0022] In the present invention, the insulating layer is preferably
formed of any one material selected from among low temperature
co-fired ceramic, high temperature co-fired ceramic, ceramic, FR-4,
epoxy, and mixtures thereof.
[0023] In the present invention, the insulating layer preferably
has a thickness of 50 .mu.m or more.
[0024] In the present invention, at least one HP LED is preferably
mounted on a single beacon.
[0025] In the present invention, the HP LED preferably further
comprises a connector to input external signals and electric
power.
[0026] In the present invention, at least one beacon is preferably
formed on a single heat spreader.
[0027] In the present invention, the wiring layer of the wiring
substrate should be positioned on the same line as the HP LED to be
wire bonded therewith. In addition, the HP LED may be attached to
the upper surface of the beacon of the heat spreader using an
adhesive having high heat conductivity. The reflection cup having a
cavity may be formed to surround the region required for mounting
the HP LED, and the short-circuit prevention layer may have
insulating properties to prevent the generation of electrical
short-circuit between the wiring layer of the wiring substrate and
the reflection cup.
[0028] In the present invention, the upper surface of the beacon,
on which the HP LED is mounted, may be formed into a flat
structure, a groove structure in which the HP LED may be received,
or a stepped structure. Thus, the position of the HP LED mounted on
the beacon may vary depending on the height and structure of the HP
LED. To realize a white HP LED using a blue HP LED, phosphor may be
applied in a manner that prevents it from flowing down.
[0029] The luminance of the HP LED and the angle of light
distribution-from the HP LED may be controlled by changing the tilt
angle formed by the difference between the upper and lower
diameters of the cavity of the reflection cup and the area
surrounding the HP LED. In addition, the design may be changed,
added to or deleted from, if necessary.
[0030] The height of the beacon may be controlled so that the lower
end of the cavity of the reflection cup is designed to be lower
than the light-emitting position of the HP LED. Thereby, light is
not emitted to the lower end of the HP LED, and thus, the luminous
efficiency is desirably increased.
[0031] In addition, when the HP LED is attached to the beacon of
the heat spreader, the adhesive having high heat conductivity may
be used, so as to transfer heat to the heat spreader. Therefore,
compared to conventional structures having three heat barrier
layers shown in FIGS. 3 to 5, the number of heat barrier layers of
the HP LED of the present invention may be decreased to one, and
thermal fatigue, junction temperature, and thermal resistance may
be drastically reduced.
[0032] Further, in the present invention, for heat release, the HP
LED may be attached to the beacon, and as well, the phosphor and
the encapsulant, each of which is formed of an insulating material
having heat conductivity higher than air, may be provided over the
HP LED mounted on the beacon of the heat spreader to be connected
in the cavity of the reflection cup, thus enhancing the functions
of the HP LED. Hence, heat may spread toward the reflection cup and
the wiring substrate via the encapsulant before being released to
air by convection and radiation, thereby realizing an enlarged heat
release area.
[0033] In the present invention, the HP LED package having hundreds
of lumens may be realized in the form of a multi-chip HP LED
package having multi-chip arrays, by mounting at least one HP LED
to a single beacon, and also forming a plurality of beacons on the
heat spreader.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a sectional view showing an HP LED package,
according to the present invention;
[0035] FIG. 2 is a top plan view showing the HP LED package,
according to the present invention;
[0036] FIGS. 3, 4 and 5 are sectional-views showing conventional HP
LEDs;
[0037] FIGS. 6 and 7 are sectional views showing the reflection cup
structures provided to the HP LED package, according to the present
invention;
[0038] FIGS. 8, 9 and 10 are sectional views showing the beacon
structures in the HP LED package, according to the present
invention;
[0039] FIG. 11 is a top plan view showing a plurality of HP LEDs
attached to a single beacon of a heat spreader, according to the
present invention;
[0040] FIG. 12 is a sectional view showing the array of at least
one HP LED package, according to the present invention; and
[0041] FIGS. 13 and 14 are top plan views showing the arrays of the
at least one HP LED package, according to the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] Hereinafter, a detailed description will be given of the
preferred embodiments of the present invention, with reference to
the appended drawings. Reference will now be made in detail to the
preferred embodiments of the present invention, examples of which
are illustrated in the accompanying drawings, wherein like
reference numerals refer to like elements throughout. The
description of known functions and structures, which is considered
unnecessary in the present invention, is omitted.
[0043] FIGS. 1 and 2 are a sectional view and a top plan view,
respectively, showing an HP LED package, according to the present
invention.
[0044] The HP LED package of the present invention comprises a
beacon 105, 205 processed to protrude from part of a heat spreader
109, 206; an HP LED 101a, 201 mounted on the beacon; an adhesive
101b having improved heat conductivity and used to attach the HP
LED to the beacon 105, 205; a wiring layer 102, 202 of a wiring
substrate formed on the same line as the HP LED to be electrically
connected to the HP LED; an insulating layer 103 to prevent
short-circuit between the wiring layer 102, 202 and the heat
spreader; a conduction preventing layer 106, 203 to prevent
electrical conduction between the wiring layer 102, 202 and a
reflection cup 104, 204 having a cavity; a phosphor 107 formed on
the HP LED; and an encapsulant 108 applied on the phosphor 107.
[0045] The heat spreader 109, 206 including the beacon should be
formed of a material having high heat conductivity, regardless of
the kind of metal or non-metal. In addition, the heat spreader may
be prepared using any process, including, but not being limited to,
a cutting process, an extruding process, a molding process, or a
plating process. For adhesion to the wiring substrate, in the case
of using a soldering process and a brazing process, the heat
spreader may be plated with nickel (Ni) and then silver (Ag) or
gold (Au), to increase adhesive strength. In addition, in the case
of using an adhesive, the heat spreader may be plated with nickel
(Ni) and then silver (Ag) or gold (Au), or may have a mechanically
and chemically roughened upper surface, with the exception of the
beacon, to increase adhesive strength.
[0046] FIGS. 8, 9 and 10 illustrate the beacon structures processed
in the flat-, groove- or stepped-shape to mount the HP LED thereon,
according to the present invention.
[0047] The reflection cup 104, 204 having a cavity may be easily
prepared through extrusion using copper, aluminum flake or plastic,
but is not limited to such a process. To increase reflectance and
luminance, the reflection cup may be plated. with silver (Ag). The
upper and lower diameters of the reflection cup may be controlled
to be different from each other, depending on the height of beacon
and the types of HP LED to be mounted, thus exhibiting maximum
performance.
[0048] The reflection cup having a cavity may be provided in
various shapes, depending on provision techniques, which are
illustrated in FIGS. 1, 6 and 7.
[0049] FIG. 1 illustrates a reflection cup having a cavity inserted
into the heat spreader, FIG. 6 illustrates a reflection cup
inserted into the wiring substrate, and FIG. 7 illustrates a
reflection cup attached to the wiring substrate, the above
techniques including, for example, soldering or brazing using a
solder, or a process using an adhesive, and the material being able
to be unlimitedly used.
[0050] The insulating layer 103 of the wiring substrate is formed
of low temperature co-fired ceramic (LTCC), high temperature
co-fired ceramic (HTCC), or interlayer insulating. PCB material,
for example, ceramic, FR-4, or epoxy, with a thickness of 50 .mu.m
or more. Further, it is possible to form the wiring layer on any
one selected from among a single-sided substrate, a double-sided
substrate, and a multi-layered substrate. In this regard, the
double-sided substrate, which is a substrate provided with wiring
on upper and lower surfaces thereof, may be attached to the heat
spreader by soldering, brazing and curing for compression and
drying using an adhesive or solder. The single-sided substrate,
which is a substrate provided with wiring only on an upper surface
thereof, may be provided on the heat spreader 109, 206 by
lamination through direct attachment or by printing through
application of an insulating material.
[0051] The wiring substrate has a cavity in which the beacon 105,
205 is received, in which the cavity may be formed using a cutting
process, a process of forming the cavity before lamination, or a
punching process.
[0052] The phosphor 107 may be applied on the HP LED or not,
depending on end purposes, and the encapsulant 108 may be
incorporated into the reflection cup having a cavity using epoxy or
silicon.
[0053] Turning now to FIG. 11, a plurality of HP LEDs mounted on a
single beacon is illustrated. RGB HP LEDs 1101 are combined, thus
realizing various colors, and the plurality of HP LEDs is attached
to a single beacon, thereby increasing luminance intensity. In
addition, various colors and high luminance intensity may be
achieved by applying controlled signals through at, least one
wiring pattern 1103. present outside the package, and also bonding
wires 1102 for signal connections between the HP LED and the wiring
pattern and between the HP LEDs.
[0054] FIG. 12 is a sectional view showing a multi-chip HP LED
package having performance ranging from tens of lumens (lm) to
hundreds of lumens (lm) by arranging at least one package 1201 of
FIG. 1 on a finned heat spreader 1202, and FIGS. 13 and 14 are top
plan views showing the multi-chip HP LED package.
[0055] As shown in FIG. 12, external signals and electric power are
input to the multi-chip HP LED package using a connector 1203. In
addition, depending on end purposes, the HP LED package may further
include a signal controller and thus be used as a module.
[0056] FIG. 13 illustrates the array of a plurality of HP LEDs
attached to a single beacon, which is longitudinally formed on a
heat spreader and includes a group. of reflection cups having
cavities formed on the beacon. FIG. 14 illustrates the array of a
plurality of HP LEDs attached to a single beacon, which is formed
on a heat spreader and includes a single reflection cup having a
cavity formed on the beacon.
[0057] The HP LED package thus formed has the following
properties.
[0058] The junction temperature and thermal resistance of the LED
of the present invention were measured. For comparison with the
above results, the properties of a conventional structure shown in
FIG. 5 were measured through simulation experiments. The comparison
results are shown in Tables 1 and 2, below. When the same HP LEDs
were applied, the junction temperature and thermal resistance of
the HP LED of the present invention were confirmed to be improved
by 3.8.degree. C. and 4 W/mK, respectively, due to the package
structure. TABLE-US-00001 TABLE 1 CONVENTIONAL INVENTIVE OBJECT MIN
MAX MEAN MIN MAX MEAN S_L_MBAR_1 48.27 50.38 49.28 44.48 46.60
45.50 S_L_MBAR_2 48.12 50.06 49.02 44.58 46.28 45.24 S_L_MSBAR_1
46.16 49.76 47.66 42.38 45.98 43.87 S_L_MSBAR_2 46.09 49.79 47.64
42.36 46.04 43.89 S_L_MSBAR_3 46.27 49.95 47.82 42.50 46.17 44.04
S_L_MSBAR_4 45.98 49.60 47.47 42.24 45.84 48.73 S_L_SBAR_1 45.55
46.85 46.19 41.77 43.03 42.42 S_L_SBAR_2 45.53 46.75 46.16 41.75
42.97 42.39 S_L_SBAR_3 45.36 46.58 45.97 41.61 42.84 42.25
S_L_SBAR_4 45.38 46.68 46.00 41.63 42.94 42.26 S_N_CIR_1 45.58
48.03 45.87 41.83 42.28 42.12 S_N_CIR_2 45.41 45.77 45.63 41.66
42.02 41.88 S_N_CIR_3 45.60 46.08 45.90 41.85 42.34 42.16 S_N_CIR_4
45.44 45.89 45.74 41.73 42.17 42.02 S_N_CIR_5 45.28 45.63 45.49
41.57 41.91 41.78 S_N_CIR_6 45.46 45.94 45.76 41.75 42.23 42.06
S_N_LONGBAR_1 42.66 46.94 44.10 38.86 43.17 40.31 S_N_LONGBAR_2
42.40 45.55 43.81 38.59 42.88 40.02 S_N_LONGBAR_3 42.80 46.99 44.17
39.00 43.23 40.38 JUNCTION TEMP 45.44 47.49 46.30 41.68 43.74 42.54
MEAN
[0059] TABLE-US-00002 TABLE 2 TEMPERATURE DEVIATION THERMAL
RESISTANCE CONVENTIONAL INVENTIVE CONVENTIONAL INVENTIVE
N-SOLDER.1.1 5.349 5.362 6.363 6.383 N-SOLDER.1.1.1 5.272 5.319
6.276 6.332 N-SOLDER.1.2 5.202 5.244 6.192 6.243 P-SOLDER.2 8.774
6.835 8.085 8.137 P-SOLDER.2-2 7.485 7.551 8.887 8.989 P-SOLDER.2-3
7.459 7.554 8.890 8.992 SI_SUBMOUNT 12.585 12.320 14.982 14.667
ANODE 11.982 12.024 14.265 14.314 ANODE.1 12.013 12.050 14.301
14.346 ANODE.1.1 11.268 11.310 13.414 13.464 CATHOD 10.766 10.853
12.816 12.920 CATHOD.1 12.351 12.325 14.704 14.873 CATHOD.1.1
12.204 12.163 14.529 14.503 THERMO_PASTE 18.037 14.739 21.473
17.546 METAL_SUBSTRATE 18.025 14.734 21.459 17.641
[0060] As described above, the present invention provides an HP LED
package comprising a substrate having a beacon. According to the
present invention, at least one LED is mounted on a beacon
processed to protrude from part of a heat spreader formed of metal
or non-metal having high heat conductivity, and also a wiring
substrate is attached to the heat spreader, thereby decreasing the
junction temperature and thermal resistance of the HP LED and
reducing the thermal fatigue thereof. Therefore, the HP LED package
of the present invention has high reliability, superior heat
release properties, and high luminance.
[0061] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
* * * * *